The present invention is related to air filtering systems having a filter element removable and replaceable from the filter housing. In particular, the invention is directed to air filtering systems in which access space into the assembly is limited.
Air travel is one of the most common modes of transportation in today""s society. Thousands of planes carry travelers across the country and around the world on both business and personal trips. For many of these trips, the flight is at least two hours long, and sometimes, the flight is eight hours long or more.
When airborne, the airplane is sealed and pressurized, with partial exchange of air from the atmosphere with the plane interior. What this means is that only some of the ventilation air for the passenger cabins is brought into the plane from the outside. Typically, about 50%, depending on the plane model, of air supplied to the cabin is from the outside atmosphere. This limited amount of fresh air is mixed with air from the cabin that is continuously recycled. Understandably, the cabin air can quickly become contaminated. Some people blame the air for carrying infectious viruses and other contaminants that produce illness. Even if no infectious contaminants are present, the air, nevertheless, often has a quality that is undesirable to many passengers.
Air filtration systems have been designed to remove contaminants from the recirculated air. However, these filtration systems are constrained by the severe weight and size requirements determined by the airplane manufacturer. Given these small weight and size limits, the air filtration systems have been greatly undersized for the amount of cabin air needing to be filtered. Further, the often inconvenient placement of the filtration system in the aircraft hinders access to the filter for replacement.
What is desired is an improved air filtration system for cabin air of airplanes.
The present invention is directed to an air filter system that can be installed in applications that have a minimal amount of space for retaining a filter housing and a limited amount of space for removal and replacement of the filter element from that housing. In particular, the air filter system of the present invention is adapted for use in airplanes for filtering cabin air. The light weight construction of the filter system, which includes a filter housing and a filter element, is beneficial for airplanes where weight can be critical. Additionally, the mounting system for retaining the filter element in the housing allows removing and replacing the filter element in areas with low or small clearance areas.
In one aspect of this invention, an air filtration system is provided. The air filtration system includes a housing and an air filter within the housing.
In particular, the invention is directed to an air filtration system that comprises a housing having an inlet and an outlet, the inlet receiving dirty air to an interior of the filter assembly, and the outlet receiving clean air from the interior. The housing further comprises a first rail fixedly attached to the interior of the housing and a second rail movably attached to the first rail. A filter element is positioned within the housing, the filter element comprising filtration media supported by a frame. At least one peg extends from the frame of the filter element. The system further includes a locking system for retaining the filter element within the housing. This locking system comprises the first rail fixedly attached to the interior of the housing, the first rail having a first retaining feature, such as a slot, therein. The locking system further comprises the second rail movably attached to the first rail, the second rail having a second retaining feature, such as a slot, therein. When the second rail is in an extended position, the first retaining feature is aligned with the second retaining feature, and, when the second rail is in a retracted position, the first retaining feature is offset from the second retaining feature. The peg on the filter frame is constructed and arranged to fit within the first retaining feature and the second retaining feature.
The housing has a weight no greater than about 10 kg, preferably no greater than about 8 kg, and the filter element has a weight no greater than about 5 kg, preferably no greater than about 3 kg.
In another embodiment, the invention provides an air filter system comprising a housing having an inlet, an outlet, and an interior, the housing configured to mount a filter element within the interior between the inlet and the outlet, and a filter element loading and locking mechanism. The loading and looking mechanism comprises a first guide member on the filter element, and a second guide member mounted to the housing and configured to cooperatively engage the first guide member such that the filter element can be slideably inserted into the housing by contact primarily only between the first and the second guide members. Also part of the loading and locking mechanism is a positioning mechanism in the housing for cooperatively engaging the first guide member as the filter element is being inserted into the housing for operatively positioning the filter element within the housing, and a locking mechanism for retainably locking the filter element in the operative position.
A filter element is also provided. The filter element includes a frame to support filtration media, the frame having a front side, a back side, a first side wall and a second side wall opposite the first side wall. A first peg extends from the first side wall and a second peg extends from the second side wall. A third peg can extend from the first side wall and a fourth peg can extend from the second side wall.
One specific filter element has the pegs extending from the first side wall at least 0.5 cm, the pegs on the same side wall having a distance of 28.302 cm to 28.378 cm therebetween.
Other variations of filter elements and air filtration systems in accordance with the present invention will be apparent with respect to the following Figures and Description.